[#1631]Inefficient delivery of salvage to station with multiple scrap processors/recyclers

[Falcrack]

Delivery of scrap to scrapyards with multiple scrap processors/recyclers is very inefficient, some would say bugged. Despite many manticores hovering around the station with scrap waiting to unload, and excess energy, they are not delivering to the scrapyard to fill up all the available processors. Something about the logic allowing manticores to offload their scrap at the station is off. Just before this save, I had turned off the processing and recycling modules to allow enough energy cells to accumulate.

Please take a look at this save game to see the issue, and observe it carefully over a period of time. It is only modified because it was created with a custom game start, it otherwise has no mods.

https://1drv.ms/u/s!Atd3uAJ_kttOnTOmtfN ... z?e=sGIBHy

EDIT: I really didn't have excess energy, and I think my station being short of energy is the real culprit for the station not accepting wrecks in all its scrap processing modules. When I properly scaled up the energy cell production to really make excess energy, far more of the scrap processing modules became active.

[Imperial Good]

In my experience it seems that scrap delivery manticores select a processor to unload at randomly, or possibly longest-idle, and then queue circling around that processor until they are able to unload. This means that a lot more manticores are needed to assure that all processors have at least 1 manticore circling them at any time so they get efficiently fed scrap.

I do agree that this is likely not ideal. In my opinion it would be preferable if the manticores delivering scrap could queue upon reaching the station and then the station assigns idle processors to unload at to members of the queue. A tricky part of such logic would be tracking the state that a processor has a manticore assigned to unload to it but is still idle, since if that manticore has its orders interrupted it would need to free-up that processor to be allocated to another manticore in queue.

[Falcrack]

In my experience it seems that scrap delivery manticores select a processor to unload at randomly, or possibly longest-idle, and then queue circling around that processor until they are able to unload. This means that a lot more manticores are needed to assure that all processors have at least 1 manticore circling them at any time so they get efficiently fed scrap.

I do agree that this is likely not ideal. In my opinion it would be preferable if the manticores delivering scrap could queue upon reaching the station and then the station assigns idle processors to unload at to members of the queue. A tricky part of such logic would be tracking the state that a processor has a manticore assigned to unload to it but is still idle, since if that manticore has its orders interrupted it would need to free-up that processor to be allocated to another manticore in queue.

In my experience, adding more manticores does not solve the problem, I still tend to have at least half of the processors idle while swarms of manticores with wrecks in tow are circling around.

[Mookau]

In my experience, adding more manticores does not solve the problem, I still tend to have at least half of the processors idle while swarms of manticores with wrecks in tow are circling around.

Could be that they assign themselves in advance (once they find scrap) and they either don't randomize their selection, or they prioritize ones that are idle/first in the list/whatever.

While it would be nice to get an official fix, I do believe someone made a mod to address the issue.

[TheDeliveryMan]

The current implementation of tugs picking a random processor creates some kind of https://en.wikipedia.org/wiki/Coupon_co ... 7s_problem.

If you have N scrap processors then on average you need to queue N/N + N/(N-1) + N/(N-2) + ... + N/1 tugs to keep all processors busy. For 6 processors that's about 15 tugs and for 10 processors that's about 29 tugs! So if you see a few idle processors then adding more tugs hardly helps.

[Falcrack]

I think the whole system needs a rethink, specifically the part about only allowing a single wreck/scrap cube in the scrap processor at one time. The idea of waiting until the scrap processor is done processing before you can load more wrecks or cubes is making the scrap recycling process unnecessarily complicated.

[PV_]

In my experience, adding more manticores does not solve the problem, I still tend to have at least half of the processors idle while swarms of manticores with wrecks in tow are circling around.

In my experience adding more Manticores does make more Scrap Processors occupied, but also creates more idle Manticores.

[Scoob]

I posted about this topic a little while back. I noticed that my Tugs won't even start returning to the Scrap Processor until there's a BUY order. Now, you'd expect a near-empty Scrap Processor to have a huge buy order for thousands of units of scrap. like any other "empty of a resource" station would, but no, they don't. MOST of the time, it has NO BUY ORDER AT ALL, with an order only appearing, it seems, when a processor is free. So, what I see, time and time again, is this:

Scrap Processor is processing a wreck so there is NO CURRENT BUY OFFER, this leaves other Tugs that might have collected a wreck idling right where they found it. Only when that current wreck has been processed, will a BUY order be created again, meaning ONE of the (potentially many) Tugs waiting will start to return. I monitored this closely for several hours.

Now, with just ONE Scrap Processor and being close to a solid source of wrecks - such as one of the wreckage fields - it's not too bad and things work pretty well. I assign a dozen or so Tugs, and they generally keep the Scrap Processor Supplied. So much so that I can usually have TWO Recyclers for each processor, with a solid supply of EC's. However, when you try to scale up, adding additional Scrap Processors the whole things breaks down. Despite there being MORE Scrap Processors, I can observe Tugs waiting to return far more often. In a recent game, I had a grand total of FIVE Scrap Processors, with the processed Scrap being shipped off to another station for actual Recycling. Despite literally infinite wrecks available close by - scrap field - with a compactor cubing up larger wrecks, regularly three or four of the processors were EMPTY and idle, despite streams of Tugs WAITING to return. However, despite the recyclers being empty there was no BUY offer. Station had ample storage for the processed Scrap, it's not like it was full so the Scrap Processors stopped working.

It's like something wonky happens when there's more than one Scrap Processor, confusing things. A single, empty Scrap Processor will usually generate a new BUY offer quickly after the prior wreck is offloaded - within 30 seconds or so from observation. When there's more than one Scrap Processor, it can be several minutes before a Buy Offer is generated, even if several of the processors are starving. I.e. they are NOT actively processing a wreck, they are IDLE, doing nothing.

I read elsewhere that returning Tugs will pick a random Scrap Processor, if there's more than one. If that Scrap Processor is already working and cannot accept a fresh wreck, I guess the Tug just has to try again. I don't know what the time frame for this is though. However, as MOST of the time, such a station with multiple Scrap Processors simply is NOT generating BUY orders, NO Tugs can deliver ANYTHING. One cannot even MANUALLY deliver Scrap as there's NO Buy order.

So, the situation:

STARVING Scrap Processors
LOADS of Tugs with Scrap in tow
NO Buy Offers
Tugs waiting to return (I've lost many Tugs while they just sit where they collected the wreck in a conflict area)

I mentioned this is my original post on the topic, but here's what would help:

- Fix the Queuing system, it's broken.
- Ensure Tugs start to return IMMEDIATELY upon snagging a wreck.
- Fix the Buy offers via some sort of "buffer" for wrecks.

This is needed, as Scrapping is GREAT but equally EXCEEDINGLY frustrating when it breaks down like this.

Note: I HAVE submitted a vanilla Save demonstrating this in the past. Not the prior time I posted about this, but before then, during a Beta. I can only assume that my report wasn't considered as it wasn't a "new to the beta" issue, but a long-standing one. Nevertheless, it demonstrated the issue pretty well. Not as extreme as my more recent Five Processors game, but that save used some mods, so is invalid for bug reporting of course. However, having clearly seen and demonstrated the issue in a totally Vanilla Beta version of the game previously, the Mods I use have made no difference to it.

I would LOVE to see Scrap Processors working more smoothly with the ability to scale up Processing actually yielding better results.

Note: as a "Work around" (urgh!) it seems far better to set up multiple stations to handle Scrap Processing, even if they all have the same area of operation. Shipping resultant processed Scrap to another station for Recycling into Hull Parts and Claytronics works well. Scrap Processing still needs lots of EC's of course, but it's more manageable. Recycling needs LOADS of EC's, so I place that Station in an area with more Solar output, so the build isn't too crazy.

[Falcrack]

I'm starting to think, after looking at the situation more closely, that scrap delivery is working better than I thought it was. It may just be that I was dramatically underestimating the number of energy cell production needed for my scrapyard. When I scaled up energy cell production to about 14 e cells production modules per 1 scrap processors and 1 scrap recycler (it was actually 112 energy cells, 8 scrap processors, and 8 scrap recyclers), the scrap processors are more or less actively working. I think that having too few energy cell production was causing my manticores to idle outside the station. If there is too little e cell production, the station has to balance processing the existing scrap it has into hull parts and claytronics vs producing more scrap from raw scrap. If there is abundant scrap, and no excess energy, it makes sense that the station's scrap processing modules are not accepting new wrecks, because processing raw scrap into scrap is very energetically expensive.

So my apologies for making a stink about this, and good job Egosoft. Your scrap system makes more sense than I thought it did before.